year = 2004
month = 2
if month == 4 or month == 6 or month == 9 or month == 11:
    print("30天")
else:
    if month == 2:
        if year % 100 == 0:
            if year % 400 == 0:
                print("29天")    #闰年二月份的天数
            else:
                print("28天")
        else:
            if year % 4 == 0:
                print("29天")
            else:
                print("28天")
    else:
        print("30天")
